PERIPHERAL VASCULAR PROCEDURES << BACK Carotid Angiography This test uses a contrast dye injected into one or both of the carotid or vertebral arteries in the neck to make them visible. The procedure is most frequently used to confirm cases of stroke, tumor, bulging of the artery walls, a clot, a narrowing of the arteries, and to evaluate the arteries of the head and neck before a corrective surgery.